Adhesion of platelets to microcapsules and the role of complement

Rabbit platelets rapidly adhered to carboxylated polyamide microcapsules through the adsorbed layer of plasma components. These components were found to be heat-labile proteins, which exist in fresh serum, and to demand calcium ions to function. These findings ascribed the components to the complement system. In fact, a good correlation was obtained between platelet adhesion to, and complement fixation by, the microcapsules. Moreover, the activation of the complement system by the microcapsules was assumed to proceed via the classical pathway. It was concluded that adhesion of platelets to the microcapsules is brought about by immune adherence.